Does cruise control use up more fuel than keeping a constant speed with your foot on the accelerator?

Question

I mean if you are diving on a relatively flat and straight road. Is there something in the computer that decreases fuel economy?

Answer 1

It saves you fuel no matter where you drive, for the simple reason that no person on the planet can maintain an exact speed as accurately as a cruise control. If you want proof, set it on 65 and drive down the flattest stretch of road you can find. You will be able to spot the people without cruise control because they will constantly be varying their speed, catching up to you, passing you, and falling behind you no matter how hard they try. If you disengage your cruise control, you will not be able to maintain a constant speed to within a half a mile an hour. A cruise control monitors your speed thousands and thousands of times a minute, and makes almost imperceptible changes to the throttle, giving the engine only the fuel it needs to maintain a speed. It does not get tired, it does not get fatigued, distracted, or fooled by hills or headwinds. In contrast, every time you slow down even a couple of miles an hour, it takes more fuel to return to your desired speed than it takes for the cruise control to precisely maintain it.

Answer 2

No, assuming that you can actually keep a constant speed with your foot on the accelerator, which is next to impossible to do.

Answer 3

using cruise will save fuel in flat terrain and use more fuel in hilly areas as it constatly speeds up/down from hills. cruise use or not use probably won't make a huge mileage change

Answer 4

Actually, it's more likely to increase your fuel economy.

Sort of like using the autopilot to fly the airplane at altitude, the computer makes more rapid and better decisions than you can.  

It's a little unnerving to use if you're not used to it, particularly if you've got a model that actually actuates the accelerator under your foot. Some will pick up mile or two per hour when engaged, some will stay put, some won't set above or below preset speeds.

But for the most part, it's often the most efficient way to drive when you're in an area where it's safe to use it.  

Trust me, if there's a stiff spring and a blown fuse on a six hundred mile drive, the cost of a gallon of gas for an assortment of fuses to make the cruise control work is money well spent.

JT

Answer 5

cruise wont use no more on flat roads, but it will on hilly roads

Answer 6

Cruise control is definately more economical, especially on an automatic, which is why more and more commercial vehicles are coming along with auto 'boxes and cruise - hauliers want to get more mpg's

Answer 7

Cruise control will save you gas on long trips that do not involve lots of stopping and going. The road does not have to be flat or straight. The cruise control will use very small increases and decreases to manage the fuel consumption too.

You can save fuel just by driving 5 mile under the speed limit too.